1. Field
One or more example embodiments relate to magnetic tracks, information storage devices including magnetic tracks, and methods of operating information storage devices.
2. Description of the Related Art
Non-volatile information storage devices retain recorded information even when power is cut off. Examples of conventional non-volatile information storage devices include hard disk drives (HDDs), non-volatile random access memories (RAMs), etc.
In general, an HDD may wear down due to a rotating mechanical device included in the HDD. As a result, HDDs may experience operational failures, thereby reducing reliability. Meanwhile, a representative example of a conventional non-volatile RAM is flash memory. Although conventional flash memories do not use a rotating mechanical device, these memories have relatively low reading and writing speeds, relatively short lifetimes, and smaller storage capacity than conventional HDDs. Also, conventional flash memories have relatively high manufacturing costs.
Another non-volatile memory uses movement of a magnetic domain wall of a magnetic material. A magnetic domain is a minute magnetic region in which magnetic moments are arranged in a specific direction in a ferromagnetic material. A magnetic domain wall is a border region between magnetic domains having different magnetization directions. The magnetic domain and the magnetic domain wall may be moved by supplying a current to the magnetic material. An information storage device, which has a relatively large storage capacity and does not use a rotating mechanical device, may be realized by using the movement of the magnetic domain and the magnetic domain wall.
Although a magnetic domain may have a relatively small size, (e.g., a length of about 10 nm) conventional read and write units do not have similarly small sizes due to, for example, limitations on lithographic processes. Currently, a line width of the read unit or the write unit may be reduced to between about 50 and about 60 nm, inclusive. Therefore, if a size of a magnetic domain is determined according to the size of the read unit (or the write unit), the magnetic domain cannot be shorter than between about 50 and about 60 nm, inclusive. As a result, increasing recording density is relatively difficult.